The primary objective is to evaluate the long-term safety and efficacy of LJP 394 in patients with a prior history of active lupus renal disease. Both the safety and efficacy profile of LJP 394 will be assessed during the 48-week trial. Safety and efficacy parameters include: the incidence of adverse experiences, concomitant medications, physical examinations, vital signs, changes in the results of laboratory parameters (chemistry, hematology, coagulation and urinalysis), complement (C3,C4), dsDNA antibody concentration, 24 hour urine protein and protein: creatinine ratio, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and/or British Isles Lupus Assessment Group (BILAG) assessments. SLE Damage Index and MOS SF-36 Survey.